Do you send the first (Motor1) logic card any inputs? Do you provide power? Do you provide an oscillator or other clock? How stabile is the output from the encoder? You say, " I have to Just Multipile the Pulse comming from encoder(Max 100KHz) and send it out.to other logic card which is going to control Motor 2, but what is LOgic card which I have no info. " Does that mean that the encoder always produces 100 KHz, exactly, or does it vary. If it varies, how much does it vary? Does it ever exceed 100 kHz? Does the duty cycle (time_high/time_low) ever change? Under what circumstances?

How precisely must you multiply the output from the encoder? How quickly must you respond to changes if there are any?

A phase locked loop is a circuit which uses a voltage controlled oscillator, a phase detector, and an error amplifier, possibly in combination with one or more dividers in order to produce a local copy of an input reference frequency, or a multiple of that frequency. A frequency synthesizer uses that same strategy to produce a desired frequency from another frequency of known value. In some cases very precise outputs can be derived from somewhat less precise inputs by complex and sophisitcated means. The cesium clock at the U.S. National Institute of Standards and Technology uses such techniques to provide very precise time references.

Please answer ALL the questions I've presented in this and previous messages regarding this problem of yours.

If you had already done so, you'd likely be finished now. Doing this sort of thing in the 100 kHz and lower range is quite achievable, but you must answer ALL the questions.